U.S. patent number 11,337,183 [Application Number 16/803,579] was granted by the patent office on 2022-05-17 for aggregated control information for a wireless communication network.
This patent grant is currently assigned to QUALCOMM INCORPORATED. The grantee listed for this patent is QUALCOMM Incorporated. Invention is credited to Alfred Asterjadhi, George Cherian, Padmanabhan Venkataraman Karthic, Abhishek Pramod Patil, Maarten Menzo Wentink.
United States Patent |
11,337,183 |
Asterjadhi , et al. |
May 17, 2022 |
Aggregated control information for a wireless communication
network
Abstract
This disclosure provides systems, methods, and apparatus,
including computer programs encoded on computer-readable media, for
signaling aggregated control information in a wireless
communication network. A frame format may include an aggregated
control (A-Control) field. In one aspect, the A-Control field may
be variable-length to support signaling multiple types of control
information. In some implementations, an access point may manage
multiple links (multi-link). The A-Control field may be structured
to include multi-link control information. This disclosure includes
multiple options for extending an A-Control field. Furthermore, a
receiving device may acknowledge the A-Control field using various
techniques disclosed herein.
Inventors: |
Asterjadhi; Alfred (San Diego,
CA), Cherian; George (San Diego, CA), Patil; Abhishek
Pramod (San Diego, CA), Wentink; Maarten Menzo
(Nijmegen, NL), Karthic; Padmanabhan Venkataraman
(Tamil Nadu, IN) |
Applicant: |
Name |
City |
State |
Country |
Type |
QUALCOMM Incorporated |
San Diego |
CA |
US |
|
|
Assignee: |
QUALCOMM INCORPORATED (San
Diego, CA)
|
Family
ID: |
1000006308311 |
Appl.
No.: |
16/803,579 |
Filed: |
February 27, 2020 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20200280975 A1 |
Sep 3, 2020 |
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Foreign Application Priority Data
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Feb 28, 2019 [IN] |
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201941007902 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W
72/0406 (20130101); H04W 84/12 (20130101) |
Current International
Class: |
H04W
72/04 (20090101); H04W 84/12 (20090101) |
Field of
Search: |
;370/229,230,252,328,329,330,473,474,476,496,522 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2854468 |
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Apr 2015 |
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EP |
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2008008918 |
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Jan 2008 |
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WO |
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2016149292 |
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Sep 2016 |
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WO |
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Other References
"PCT Application No. PCT/US2020/020276 International Search Report
and Written Opinion", dated May 21, 2020, 13 pages. cited by
applicant.
|
Primary Examiner: Ngo; Nguyen H
Attorney, Agent or Firm: DeLizio Law, PLLC
Claims
What is claimed is:
1. A method of wireless communication, comprising: determining a
plurality of control parameters for transmission from a first
wireless communication device to a second wireless communication
device, each control parameter including at least a Control
identifier (ID) and a control value; generating an aggregated media
access control (MAC) protocol data unit (A-MPDU) including a first
MAC protocol data unit (MPDU) for transmission via a first wireless
link, wherein the first MPDU includes an aggregated control
(A-Control) field formatted with the plurality of control
parameters, and wherein the A-MPDU includes an MPDU delimiter
having an indicator indicating that the first MPDU includes the
A-Control field and that the A-Control field is a variable-length
A-Control field; and outputting the A-MPDU including the first MPDU
for transmission from the first wireless communication device to
the second wireless communication device.
2. The method of claim 1, further comprising: determining a length
of the A-Control field based, at least in part, on the plurality of
control parameters; and populating a first portion of the A-Control
field with an indication based on the length.
3. The method of claim 2, wherein the first portion is formatted as
a first control parameter, the first control parameter having a
reserved value for the Control ID and having the length as the
control value for the first control parameter.
4. The method of claim 1, wherein the first MPDU only contains the
variable-length A-Control field, wherein the indicator is included
in a length field of the MPDU delimiter, and wherein the indicator
has a value that is less than a smallest length of an MPDU
according to a technical standard, such that the value is reserved
to repurpose the length field for indicating the presence of the
variable-length A-Control field in the first MPDU.
5. The method of claim 1, wherein the A-Control field is a
multi-link control field and includes a first subset of the
plurality of control parameters related to the first wireless link
and a second subset of plurality of control parameters related to a
second wireless link managed by the first wireless communication
device.
6. The method of claim 5, further comprising: generating a second
frame for transmission via the second wireless link, wherein the
second frame includes a redundant copy of the A-Control field
formatted with the plurality of control parameters; and outputting
the second frame for transmission from the first wireless
communication device to the second wireless communication device
via the second wireless link.
7. The method of claim 5, wherein the plurality of control
parameters includes at least one control parameter to enable or
disable at least one of the first wireless link or the second
wireless link.
8. The method of claim 7, wherein the plurality of control
parameters includes timing information related when to enable or
disable the first wireless link or the second wireless link, the
timing information including either a time offset relative to a
start or end of the first MPDU, or a time value based on a
synchronized timer.
9. The method of claim 5, wherein the A-Control field includes a
delimiter between the first subset of control parameters and the
second subset of control parameters.
10. The method of claim 9, wherein the delimiter is formatted as a
first control parameter, the first control parameter having a
reserved value for the Control ID and having a null control
value.
11. The method of claim 1, further comprising: receiving an
acknowledgment from the second wireless communication device,
wherein the acknowledgment indicates that the A-Control field was
successfully processed by the second wireless communication device,
and wherein the acknowledgment is different from a MAC
acknowledgment for acknowledging the first MPDU.
12. The method of claim 11, wherein the acknowledgment is included
in a reserved bit of a frame control field or block acknowledgment
control field.
13. The method of claim 11, wherein the acknowledgement includes
signaling to indicate that the acknowledgement is for the plurality
of control parameters.
14. The method of claim 13, wherein the acknowledgment is included
in a multi-station block acknowledgment (multi-STA Block Ack)
message.
15. The method of claim 14, wherein the signaling includes
predefined values for an acknowledgement type field and a traffic
identifier field of the multi-STA Block Ack message.
16. The method of claim 1, wherein the first MPDU includes the
A-Control field in a payload portion of a null packet, a quality-of
service (QoS) Null frame, or a null data packet (NDP).
17. An apparatus, comprising: at least one processor: at least one
memory communicatively coupled with the at least one processor and
storing processor-readable code, the at least one processor
configured to execute the processor-readable code and cause the
apparatus to: determine a plurality of control parameters for
transmission to a first wireless communication device, each control
parameter including at least a Control identifier (ID) and a
control value; and generate an aggregated media access control
(MAC) protocol data unit (A-MPDU) including a first MAC protocol
data unit (MPDU), wherein the first MPDU includes an aggregated
control (A-Control) field formatted with the plurality of control
parameters, and wherein the A-MPDU includes an MPDU delimiter
having an indicator indicating that the first MPDU includes the
A-Control field and that the A-Control field is a variable-length
A-Control field; and an interface configured to: output the A-MPDU
including the first MPDU for transmission to the first wireless
communication device.
18. The apparatus of claim 17, wherein the at least one processor
is further configured to execute the processor-readable code and
cause the apparatus to: determine a length of the A-Control field
based, at least in part, on the plurality of control parameters;
and populate a first portion of the A-Control field with an
indication based on the length.
19. The apparatus of claim 18, wherein the first portion is
formatted as a first control parameter, the first control parameter
having a reserved value for the Control ID and having the length as
the control value for the first control parameter.
20. The apparatus of claim 17, wherein the indicator is included in
a length field of the MPDU delimiter, and wherein the indicator has
a value that is less than a smallest length of an MPDU according to
a technical standard, such that the value is reserved to repurpose
the length field for indicating the presence of the variable-length
A-Control field.
21. The apparatus of claim 17, wherein the interface is further
configured to: receive an acknowledgment from the first wireless
communication device, wherein the acknowledgment indicates that the
A-Control field was successfully processed by the first wireless
communication device, and wherein the acknowledgment is different
from a MAC acknowledgment for acknowledging the first MPDU.
22. The apparatus of claim 17, further comprising: a transmitter
configured to transmit the A-MPDU to the first wireless
communication device, wherein the apparatus is configured as a
second wireless communication device.
23. A first wireless communication device for use in a wireless
local area network comprising: at least one processor; at least one
memory communicatively coupled with the at least one processor and
storing processor-readable code, the at least one processor
configured to execute the processor-readable code and cause the
first wireless communication device to: determine a plurality of
control parameters for transmission from the first wireless
communication device to a second wireless communication device,
each control parameter including at least a Control identifier (ID)
and a control value, and generate an aggregated media access
control (MAC) protocol data unit (A-MPDU) including a first MAC
protocol data unit (MPDU) that includes an aggregated control
(A-Control) field formatted with the plurality of control
parameters, wherein the A-MPDU includes an MPDU delimiter having an
indicator indicating that the first MPDU includes the A-Control
field and that the A-Control field is a variable-length A-Control
field; one or more antennas; and one or more transceivers
configured to transmit, via the one or more antennas, the A-MPDU
including the first MPDU from the first wireless communication
device to the second wireless communication device.
24. An apparatus, comprising: at least one processor: at least one
memory communicatively coupled with the at least one processor and
storing processor-readable code, the at least one processor
configured to execute the processor-readable code and cause the
apparatus to: determine a plurality of control parameters for
transmission to a first wireless communication device, each control
parameter including at least a Control identifier (ID) and a
control value; and generate a first frame including an aggregated
control (A-Control) field formatted with the plurality of control
parameters, wherein the A-Control field is a multi-link control
field and includes a first subset of the plurality of control
parameters related to a first wireless link and a second subset of
plurality of control parameters related to a second wireless link,
and wherein the plurality of control parameters includes timing
information indicating when to enable or disable the first wireless
link or the second wireless link, the timing information including
either a time offset relative to a start or end of the first frame,
or a time value based on a synchronized timer; and an interface
configured to: output the first frame for transmission to the first
wireless communication device.
25. The apparatus of claim 24, further comprising: a transmitter
configured to transmit the first frame to the first wireless
communication device, wherein the apparatus is configured as a
second wireless communication device.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
This patent application claims priority to Indian Provisional
Patent Application No. 201941007902, filed Feb. 28, 2019, entitled
"AGGREGATED CONTROL INFORMATION FOR A WIRELESS COMMUNICATION
NETWORK," and assigned to the assignee hereof. The disclosure of
the prior application is considered part of and is incorporated by
reference in this patent application.
TECHNICAL FIELD
This disclosure relates to the field of wireless communication, and
more specifically, to aggregated control information in a wireless
local area network (WLAN).
DESCRIPTION OF THE RELATED TECHNOLOGY
A wireless local area network (WLAN) may be formed by one or more
access points (APs) that provide a shared wireless communication
medium for use by a number of client devices, also referred to as
stations (STAs). The basic building block of a WLAN conforming to
the Institute of Electrical and Electronics Engineers (IEEE) 802.11
family of standards is a Basic Service Set (BSS), which is managed
by an AP. Each BSS is identified by a Basic Service Set Identifier
(BSSID) that is advertised by the AP. An AP periodically broadcasts
beacon frames to enable any STAs within wireless range of the AP to
establish or maintain one or more communication links with the
WLAN.
Devices in a WLAN may share control information to maintain or
share status. As communication protocols for WLANs have evolved,
there has been an effort to maintain backward compatibility.
Therefore, existing techniques for sharing control information may
be constrained by earlier versions of a communication protocol.
Meanwhile, more control information may be useful in some WLAN
deployments.
SUMMARY
The systems, methods, and devices of this disclosure each have
several innovative aspects, no single one of which is solely
responsible for the desirable attributes disclosed herein.
One innovative aspect of the subject matter described in this
disclosure can be implemented as a method performed by a first
wireless local area network (WLAN) device for wireless
communication. The method may include determining a plurality of
control parameters for transmission from a first wireless
communication device to a second wireless communication device.
Each control parameter may include at least a Control identifier
(ID) and a control value. The method may include generating a first
frame for transmission via a first wireless link. The first frame
may include an aggregated control (A-Control) field formatted with
the plurality of control parameters. The method may include
outputting the first frame for transmission from the first wireless
communication device to the second wireless communication
device.
In some implementations, the A-Control field may be a
variable-length control field.
In some implementations, a length of the A-Control field may be
determined based on a negotiation between first wireless
communication device and the second wireless communication device.
The negotiation may occur either during or after a wireless
association and before outputting the first frame
In some implementations, the method may include determining a
length of the A-Control field based, at least in part, on the
plurality of control parameters. The method may include populating
a first portion of the A-Control field with an indication based on
the length.
In some implementations, the first portion may be formatted as a
first control parameter, the first control parameter having a
reserved value for the Control ID and having the length as the
control value for the first control parameter.
In some implementations, the reserved value may include a series of
binary ones.
In some implementations, the first frame may have a frame format of
a control frame.
In some implementations, the first frame may be first media access
control (MAC) protocol data unit (MPDU).
In some implementations, the first MPDU may be included in an
aggregated MPDU (A-MPDU) transmission.
In some implementations, an MPDU delimiter in the A-MPDU
transmission may include an indicator to indicate that the first
MPDU includes the A-Control field and that the A-Control field is a
variable-length A-Control field.
In some implementations, the first MPDU may only contain the
variable-length A-Control field. The indicator may be included in a
length field of the MDPU delimiter. The indicator may have a value
that is less than a smallest length of an MPDU according to a
technical standard, such that the value is reserved to repurpose
the length field for indicating the presence of the variable-length
A-Control field in the first MPDU.
In some implementations, the plurality of control parameters may
include a first subset of control parameters related to the first
wireless link and a second subset of control parameters related to
a second wireless link managed by the first wireless communication
device.
In some implementations, the A-Control field may include the first
subset of control parameters and the second subset of control
parameters, and the A-Control field may be a multi-link control
field.
In some implementations, the method may include generating a second
frame for transmission via the second wireless link. The second
frame includes a redundant copy of the A-Control field formatted
with the plurality of control parameters. The method may include
outputting the second frame for transmission from the first
wireless communication device to the second wireless communication
device via the second wireless link.
In some implementations, the plurality of control parameters may
include at least one control parameter to enable or disable at
least one of the first wireless link or the second wireless
link.
In some implementations, the plurality of control parameters may
include timing information related when to enable or disable the
first wireless link or the second wireless link.
In some implementations, the timing information may include a time
offset relative to a start or end of the first frame.
In some implementations, the timing information may include a time
value based on a timer synchronized between the first wireless
communication device and the second wireless communication
device.
In some implementations, the timer may be synchronized for the
first wireless link, the second wireless link, or both the first
and second wireless links.
In some implementations, the A-Control field may include a
delimiter between the first subset of control parameters and the
second subset of control parameters.
In some implementations, the delimiter may be formatted as a first
control parameter. The first control parameter may have a reserved
value for the Control ID and having a null control value.
In some implementations, the method may include receiving an
acknowledgment from the second wireless communication device. The
acknowledgment may indicate that the A-Control field was
successfully processed by the second wireless communication
device.
In some implementations, the acknowledgment may be different from a
media access control (MAC) acknowledgment for acknowledging the
first frame.
In some implementations, the acknowledgment may be included in a
reserved bit of a frame control field or block acknowledgment
control field.
In some implementations, the acknowledgement may include signaling
to indicate that the acknowledgment is for the plurality of control
parameters.
In some implementations, the acknowledgment may be included in a
multi-station block acknowledgment (multi-STA Block Ack)
message.
In some implementations, the signaling may include predefined
values for an acknowledgment type field and a traffic identifier
field of the multi-STA Block Ack message.
In some implementations, the first frame may include the A-Control
field in a payload portion of a null packet, a quality-of-service
(QoS) Null frame, or a null data packet (NDP).
Another innovative aspect of the subject matter described in this
disclosure can be implemented as a computer-readable medium having
stored therein instructions which, when executed by a processor,
causes the processor to perform any one of the above methods.
Another innovative aspect of the subject matter described in this
disclosure can be implemented as an apparatus having an interface
for communicating via a wireless local area network and a
processor. The processor may be configured to perform any one of
the above methods.
Another innovative aspect of the subject matter described in this
disclosure can be implemented as system including means for
implementing any one of the above methods.
Details of one or more implementations of the subject matter
described in this disclosure are set forth in the accompanying
drawings and the description below. Other features, aspects, and
advantages will become apparent from the description, the drawings,
and the claims. Note that the relative dimensions of the following
figures may not be drawn to scale.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a system diagram of an example wireless local area
network (WLAN) for introducing concepts of this disclosure.
FIG. 2A shows a diagram of an example physical layer convergence
procedure (PLCP) protocol data unit (PPDU) frame.
FIG. 2B shows a diagram of an example aggregated media access
control (MAC) protocol data unit (A-PPDU) frame.
FIG. 3 shows a diagram of an example MAC frame with an Aggregated
Control (A-Control) field.
FIG. 4 shows an example of using a first portion to indicate the
length of a field that has aggregated control information.
FIG. 5A shows a first example of an A-Control field that includes
control parameters for multiple wireless links.
FIG. 5B shows a second example of an A-Control field that includes
control parameters for multiple wireless links.
FIG. 6 shows an example of explicit indicators for multi-link
aggregated control parameters.
FIG. 7 shows another example of an A-Control field with control
parameters for multiple links.
FIG. 8 shows an example of an A-Control field with control
parameters for multiple links without using delimiters.
FIG. 9 depicts a conceptual diagram of an example configuration
message for use in a WLAN.
FIG. 10 shows a block diagram of an example wireless communication
device.
FIG. 11A shows a block diagram of an example AP.
FIG. 11B shows a block diagram of an example STA.
FIG. 12 depicts a flowchart with example operations for a STA to
send aggregated control information.
FIG. 13 shows an example physical layer convergence protocol (PLCP)
protocol data unit (PPDU) usable for communications between a first
device and a second device.
FIG. 14 depicts an example message flow diagram associated with
acknowledging an MPDU that includes an A-Control field.
FIG. 15 shows a block diagram of an example electronic device.
Like reference numbers and designations in the various drawings
indicate like elements.
DETAILED DESCRIPTION
The following description is directed to certain implementations
for the purposes of describing the innovative aspects of this
disclosure. However, a person having ordinary skill in the art will
readily recognize that the teachings herein can be applied in a
multitude of different ways. The examples in this disclosure are
based on wireless local area network (WLAN) communication according
to the Institute of Electrical and Electronics Engineers (IEEE)
802.11 wireless standards. However, the described implementations
may be implemented in any device, system or network that is capable
of transmitting and receiving radio frequency (RF) signals
according to one or more of the IEEE 802.11 standards, the
Bluetooth.RTM. standard, code division multiple access (CDMA),
frequency division multiple access (FDMA), time division multiple
access (TDMA), Global System for Mobile communications (GSM),
GSM/General Packet Radio Service (GPRS), Enhanced Data GSM
Environment (EDGE), Terrestrial Trunked Radio (TETRA),
Wideband-CDMA (W-CDMA), Evolution Data Optimized (EV-DO),
1.times.EV-DO, EV-DO Rev A, EV-DO Rev B, High Speed Packet Access
(HSPA), High Speed Downlink Packet Access (HSDPA), High Speed
Uplink Packet Access (HSUPA), Evolved High Speed Packet Access
(HSPA+), Long Term Evolution (LTE), AMPS, or other known signals
that are used to communicate within a wireless, cellular or
internet of things (IoT) network, such as a system utilizing 3G,
4G, 5G, 6G, or further implementations thereof, technology.
A wireless local area network (WLAN) in a home, apartment,
business, or other areas may include one or more WLAN devices. Each
WLAN device may have a station (STA) interface which is an
addressable entity that shares a wireless communication medium with
other STAs. An access point (AP) is a WLAN device that includes a
STA interface as well as a distribution system access function. For
brevity in this disclosure, WLAN devices may be referred to as
STAs, regardless of whether the WLAN device is an AP or a non-AP
STA. A first wireless communication device (acting as a sending
STA) may communicate data to a second wireless communication device
(acting as a receiving STA) via a wireless channel. A technical
standard may define formats for communications. For example, the
first wireless communication device may prepare and transmit a
media access control (MAC) protocol data unit (MPDU) according to a
standardized format. An MPDU also may be referred to as a frame or
a packet in some aspects of this disclosure. A physical convergence
layer (PHY) protocol data unit (PPDU) may include one or more
MPDUs. For example, one type of PPDU (referred to as an Aggregated
MPDU, or A-MPDU) may include multiple MPDUs in a payload of the
AMPDU.
In legacy technical standards, control information may be
structured according to a fixed length field and defined bit
locations for different control parameters. More recently, the
quantity and type of control parameters has increased, making
legacy control formats insufficient. Furthermore, the fixed length
of legacy control formats limits the type and quantity of control
parameters that can be included in a frame. To provide some greater
flexibility, an aggregated control (A-Control) field may include
multiple control parameters. Each control parameter (sometimes also
referred to as a control field or a control subfield) may include a
control identifier (Control ID) and a control value.
In accordance with this disclosure, an A-Control field may be a
Dynamic A-Control field (also referred to as an Enhanced A-Control
field). For example, the A-Control field may be a variable-length
field in an MPDU. In some implementations, the length of the
A-Control field may be negotiated between two wireless
communication devices, such as at time of wireless association. In
some implementations, a first portion of the A-Control field may
indicate the length of the A-Control field. For example, the first
portion may be formatted as a control header (sometimes also
referred to as a control delimiter or delimiter). The control
header may have a format mimicking a control parameter within the
A-Control field. For example, the control header may be structured
similarly to the control parameters and may have a specific value
(such as a series of binary ones) for the Control ID. The specific
value indicates that the control header is a type of control
parameter that contains the length of the A-Control field. The
control header may be included as the first control parameter of
the A-Control field to indicate the length of the A-Control field.
Alternatively, the control header may be located at any location
within the A-Control field and can indicate either the length of
the full A-Control field or of the remaining portion (following the
control header) of the A-Control field. Thus, the A-Control field
may be variable-length to support signaling multiple types of
control information. For example, the length of the A-Control field
may vary between 4 bytes (baseline) and 64 bytes (as an example
maximum). The length of the A-Control field may be indicated by a
length value and the length value may represent groups of octets
(such as 1, 2, or 4 octets for each integer length value).
In some implementations, the specific control ID may be all ones
(in which case, assuming the control ID is 4 bits long, the
all-ones binary value would have a decimal value of 15). Although
the all-ones example is used in this disclosure, the specific value
may be any value that is supported by the recipient and that is not
used as a control ID for other purposes. Following the specific
control ID, the control information in the control header may
indicate the length value as either a zero-length value, a non-zero
value, or an all-ones length value. For example, a control
parameter referred to as "ONES-NZL" (all ones for Control ID
followed by a non-zero length value less than a maximum value) may
indicate that the A-Control field is a variable-length A-Control
field having a length indicated by the non-zero length value. In
some implementations, a control parameter referred to as a
"ONES-EOF" (all ones for Control ID followed by all ones for the
value) may indicate an end of the A-Control field. A control
parameter referred to as "ONES-ZL" (all ones for Control ID
followed by a zero-length value) may be used as a delimiter between
different subsets of the control parameters included in the
A-Control field.
In some implementations, a device may operate simultaneously or at
different times with multiple links (multi-link, multi-channel, or
multi-bands). The A-Control field may be structured to include
multi-link control information. For example, the A-Control field
may include a first subset of control parameters for a first
wireless link and a second subset of control parameters for a
second wireless link. For example, the A-Control field may include
signaling for indicating control information that governs or helps
the functionality of a link. As an example, the signaling may
include signaling for dynamic enabling or disabling each of the
wireless links.
This disclosure includes a variety of techniques for signaling
multi-link control information. For example, each of the links may
be identified using explicit signaling or implicitly based on one
or more of the structure of the A-Control field, certain bit
settings in frames that carry the A-Control field, or the link
(such as the channel or band) at which the frame is exchanged.
Therefore, the identifier of the link of interest may be determined
from the A-Control field or the frame that carries the A-Control
field. For example, a link may be identified by certain bits
preceding each set of Control parameters. In another example, the
link may be identified by certain bits contained in the frame that
carries the A-Control field. In some implementations, the A-Control
field may contain a link identifier or delimiter to signal the
beginning or end of a subset of control parameters for each link.
In some implementations, the MPDU may be a Management frame
containing an information element (IE) identifying the link of
interest. In some implementations, the link identifier may be
contained in the QoS Control field or any other field of the MAC
header that precedes the field containing the A-Control field. For
example, the most significant bit (MSB) of the traffic indicator
(TID) field of the QoS Control field is currently reserved and set
to 0. In some implementations, the setting of the MSB of the TID
field to 1 may be used to indicate that the control information
being provided by the A-Control field that follows in the same MPDU
is relative to the secondary link (different from the primary link
on which the MPDU is being sent). The primary link is the link
where the frame is being sent, and the secondary link is the link
where the frame is not being sent. Using just one bit (such as the
MSB of the TID field), the transmitting device may distinguish up
to two links. The transmitting device may include MPDUs with
different values of the MSB bit of the TID of the QoS Control if it
wants to signal different control information for the two different
links. For example, a first MPDU (with the MSB of the TID set to 0)
may include an A-Control field with aggregated control information
for the primary link. A second MPDU (with the MSB of the TID set to
1) may include an A-Control field with control information for the
secondary link.
In some implementations, the ONES-NZL may be the first control
parameter in the A-Control field and may indicate an overall length
of the Dynamic A-Control (with control parameters for multiple
links). After a first subset of control parameters (such as for the
first wireless link), a delimiter may indicate whether control
parameters for the next link is included. If no control information
is available for the link, then a ONES-ZL may be used.
Alternatively, the ONES-ZL may precede the control information for
each of the additional links. In some implementations, a ONES-EOF
or Padding can be used to populate a remaining portion of the
Dynamic A-Control field.
The A-Control field described in this disclosure may be included in
any type of frame, including a management frame, a data frame, or a
control frame. The A-Control field also may be included in a PPDU
that does not contain a Data field. For example, the A-Control
field may be included as a field of the PHY header of the PPDU
without having a data field. In some implementations, the A-Control
field may be included in an MPDU that is part of an A-MPDU with
multiple frames. In some implementations, the A-Control field may
be included in a payload of a null frame (such as a
quality-of-service, QoS, Null frame or a null data packet
(NDP)).
Particular implementations of the subject matter described in this
disclosure can be implemented to realize one or more of the
following potential advantages. An A-Control field may be a
variable-length to support the growing quantity of control
parameters that may be signaled. Furthermore, an A-Control field
may be used to include control parameters for multiple links.
Multi-link communication presents an opportunity for APs and STAs
to coexist concurrently on multiple channels that can be enabled or
disabled as needed (based on bandwidth need or to avoid
interference with other systems, reduce power consumption by
selectively turning off links that are not in use, providing fast
feedback for different links via other links to quickly adapt to
the medium conditions or systems requirements, or the like.
FIG. 1 depicts a system diagram of an example WLAN for introducing
concepts of this disclosure. FIG. 1 includes a block diagram of an
example wireless communication network 100. According to some
aspects, the wireless communication network 100 can be an example
of a WLAN such as a Wi-Fi network (and will hereinafter be referred
to as WLAN 100). For example, the WLAN 100 can be a network
implementing at least one of the IEEE 802.11 family of standards
(such as that defined by the IEEE 802.11-2016 specification or
amendments thereof). The WLAN 100 may include numerous wireless
communication devices such as an AP 102 and multiple STAs 104
having wireless associations with the AP 102. The IEEE 802.11-2016
specification defines a STA as an addressable unit. An AP is an
entity that contains at least one STA and provides access via a
wireless medium (WM) for associated STAs to access a distribution
service (such as another network 140). Thus, an AP includes a STA
and a distribution system access function (DSAF). In the example of
FIG. 1, the AP 102 may be connected to a gateway device (not
shown), which provides connectivity to the other network 140. The
DSAF of the AP 102 may provide access between the STAs 104 and
another network 140. While AP 102 is described as an access point
using an infrastructure mode, in some implementations, the AP 102
may be a traditional STA which is operating as an AP. For example,
the AP 102 may be a STA capable of operating in a peer-to-peer mode
or independent mode. In some other examples, the AP 102 may be a
software AP (SoftAP) operating on a computer system.
Each of the STAs 104 also may be referred to as a mobile station
(MS), a mobile device, a mobile handset, a wireless handset, an
access terminal (AT), a user equipment (UE), a subscriber station
(SS), or a subscriber unit, among other possibilities. The STAs 104
may represent various devices such as mobile phones, personal
digital assistant (PDAs), other handheld devices, netbooks,
notebook computers, tablet computers, laptops, display devices (for
example, TVs, computer monitors, navigation systems, among others),
wearable devices, music or other audio or stereo devices, remote
control devices ("remotes"), printers, kitchen or other household
appliances, key fobs (for example, for passive keyless entry and
start (PKES) systems), among other possibilities.
The AP 102 and the associated STAs 104 may be referred to as a
basic service set (BSS), which is managed by the AP 102. A BSS
refers to one STA (such as an AP) that has established service
settings and one or more STAs that have successfully synchronized
the service settings. Alternatively, a BSS may describe a set of
STAs that has synchronized matching mesh service profiles. Using
the example architecture in FIG. 1, the BSS may be identified by a
service set identifier (SSID) that is advertised by the AP 102. The
AP 102 may periodically broadcast beacon frames ("beacons") to
enable any STAs 104 within wireless range of the AP 102 to
establish or maintain a respective communication link 106 (also
referred to as a "Wi-Fi link" or "wireless association") with the
AP. An "unassociated STA" (not shown) may not be considered part of
the BSS because they do not have a wireless session established at
the AP 102. The various STAs 104 in the WLAN may be able to
communicate with external networks as well as with one another via
the AP 102 and respective communication links 106. To establish a
communication link 106 with an AP 102, each of the STAs is
configured to perform passive or active scanning operations
("scans") on frequency channels in one or more frequency bands (for
example, the 2.4 GHz, 5 GHz, 6 GHz or 60 GHz bands). To perform
passive scanning, a STA listens for beacons, which are transmitted
by respective APs 102 at a periodic time interval referred to as
the target beacon transmission time (TBTT) (measured in time units
(TUs) where one TU is equal to 1024 microseconds (s)). To perform
active scanning, a STA 104 generates and sequentially transmits
probe requests on each channel to be scanned and listens for probe
responses from APs 102. Each STA 104 may be configured to identify
or select an AP 102 with which to associate based on the scanning
information obtained through the passive or active scans, and to
perform authentication and association operations to establish a
communication link with the selected AP.
FIG. 1 additionally shows an example coverage area 108 of the AP
102, which may represent a basic service area (BSA) of the WLAN
100. While one AP 102 is shown in FIG. 1, the WLAN 100 can include
multiple APs 102. As a result of the increasing ubiquity of
wireless networks, a STA 104 may have the opportunity to select one
of many BSSs within range of the STA 104 or select among multiple
APs 102 that together form an extended service set (ESS) including
multiple connected BSSs. An extended network station associated
with the WLAN 100 may be connected to a wired or wireless
distribution system that may allow multiple APs 102 to be connected
in such an ESS. As such, a STA 104 can be covered by more than one
AP 102 and can associate with different APs 102 at various times
for different transmissions. Additionally, after association with
an AP 102, a STA 104 also may be configured to periodically scan
its surroundings to find a more suitable AP with which to
associate. For example, a STA 104 that is moving relative to its
associated AP 102 may perform a "roaming" scan to find another AP
having more desirable network characteristics such as a greater
received signal strength indicator (RSSI).
The APs 102 and STAs 104 may function and communicate (via the
respective communication links 106) according to the IEEE 802.11
family of standards (such as that defined by the IEEE 802.11-2016
specification or amendments thereof including, but not limited to,
802.11aa, 802.11ah, 802.11aq, 802.11ay, 802.11ax, 802.11be
(802.11-EHT), 802.11az, and 802.11ba). These standards define the
WLAN radio and baseband protocols for the physical (PHY) and medium
access control (MAC) layers. The APs 102 and STAs 104 transmit and
receive frames (hereinafter also referred to as wireless
communications") to and from one another in the form of physical
layer convergence protocol (PLCP) protocol data units (PPDUs. Each
PPDU is a composite frame that includes a PLCP preamble and header
as well as one or more MAC protocol data units (MPDUs).
The APs 102 and STAs 104 in the WLAN 100 may transmit PPDUs over an
unlicensed spectrum, which may be a portion of spectrum that
includes frequency bands traditionally used by Wi-Fi technology,
such as the 2.4 GHz band, the 5 GHz band, the 60 GHz band, the 3.6
GHz band, and the 900 MHz band. Some implementations of the APs 102
and STAs 104 described herein also may communicate in other
frequency bands, such as the 6 GHz band, which may support both
licensed and unlicensed communications. The APs 102 and STAs 104
also can be configured to communicate over other frequency bands
such as shared licensed frequency bands, where multiple operators
may have a license to operate in the same or overlapping frequency
band or bands.
Each of the frequency bands may include multiple sub-bands or
frequency channels. For example, PPDUs conforming to the IEEE
802.11n, 802.11ac, 802.11ax, and 802.11-extreme high throughput
(EHT) standard amendments may be transmitted over the 2.4 and 5 GHz
bands, each of which is divided into multiple 20 MHz channels. As
such, these PPDUs are transmitted over a physical channel having a
minimum bandwidth of 20 MHz. But larger channels can be formed
through channel bonding. For example, PPDUs conforming to the IEEE
802.11n, 802.11ac, 802.11ax, and 802.11be (802.11-EHT) standard
amendments may be transmitted over physical channels having
bandwidths of 40 MHz, 80 MHz or 160 MHz by bonding together two or
more 20 MHz channels. For example, IEEE 802.11n described the use
of 2 channels (for a combined 40 MHz bandwidth) and defined a High
Throughput (HT) transmission format. IEEE 802.11ac described the
use of 8 channels (for a combined 160 MHz bandwidth) and defined a
Very High Throughput (VHT) transmission format. IEEE 802.11ax also
supports a combined 160 MHz bandwidth (which is a combination of 8
channels of 20 MHz width each). For brevity, this disclosure
includes descriptions of IEEE 802.11ax devices as an example. In
IEEE 802.11ax, a transmission format may spread High Efficiency
(HE) modulated symbols throughout a combined channel group.
The AP 102 may be an example of a first wireless communication
device 110. Regardless of whether the first wireless communication
device 110 is an AP or a traditional STA, it may be referred to as
a "sending STA" for the examples in this disclosure. The STAs 104
may be examples of the second wireless communication device 120 and
may be referred to as a "receiving STA" in the examples in this
disclosure. To be clear, the designations of sending STA and
receiving STA may be reversed in other examples. The first wireless
communication device 110 may send MPDU transmissions 116 to the
second wireless communication device 120.
The first wireless communication device 110 (as sending device) may
include an A-Control field generation unit 112 and a transmission
unit 114. The A-Control field generation unit 112 may implement the
A-Control field structure in accordance with aspects of this
disclosure. The transmission unit 114 may prepare and communicate
the MPDU transmissions 116. The second wireless communication
device 120 (as receiving STA) may include A-Control field
processing unit 122 and a reception unit 124. The A-Control field
processing unit 122 may implement the A-Control field structure in
accordance with aspects of this disclosure. In some instances, the
first wireless communication device 110 and the second wireless
communication device 120 may exchange service discovery frames or
other management frames to ascertain whether both devices support
the extended A-Control field or particular features of the
A-Control field as described herein.
FIG. 2A is a diagram illustrating an example physical layer
convergence procedure (PLCP) protocol data unit (PPDU) frame 200.
As shown in FIG. 2A, the PPDU frame 200 includes a physical layer
(PHY) header 215 and one or more PLCP service data units (such as
PSDU 280). Each of the PSDUs may be addressed to a receiver
(individually addressed), a group of receivers (group addressed),
or to all receivers (broadcast addressed). Similarly, it may be
sent by a transmitter, a group of transmitters, or all
transmitters, or a combination of both. The PDSU 280 includes zero
or more MPDUs. In FIG. 2A, the PSDU 280 includes one MPDU. Each
MPDU may include one or more of the following fields: a MAC header
field 250, a payload/data field 260, and a frame check sequence
(FCS) field 270. The PSDU 280 also may be referred to as a payload
portion 280 of the PPDU frame 200. The PHY header 215 may be used
to acquire an incoming signal (such as an OFDMA signal), to train
and synchronize a demodulator, and may aid in demodulation and
delivery of the payload portion 280.
In some implementations, the MPDUs may be included in the PSDU 280
as part of an aggregated MPDU (A-MPDU), as shown in FIGS. 2B and
13.
FIG. 2B shows a diagram of an example aggregated media access
control (MAC) protocol data unit (A-PPDU) frame. The PHY header 215
is omitted for brevity. Following the PHY header, a series of MPDU
may be organized as A-MPDU subframes. Each A-MPDU subframe (such as
A-MPDU subframe 240) may include an MPDU delimiter 290, an MPDU
292, and padding 298. The MPDU 292 may have a similar structure as
described with regard to FIG. 2A. For example, the MPDU 292 may
include one or more of the following fields: a MAC header field
250, a payload/data field 260, and a frame check sequence (FCS)
field 270.
FIG. 3 shows a diagram of an example medium access control (MAC)
frame with an Aggregated Control (A-Control) field. In some
implementations, the MAC frame 300 may include a media access
control protocol data unit (MPDU) frame. In some implementations,
the MAC frame 300 may correspond to the payload portion 280, as
previously described in FIG. 2. As shown, the MAC frame 300
includes one or more of several different fields: a frame control
(FC) field 310, a duration/identification field 325, a receiver
address (A1) field 330, a transmitter address (A2) field 335, a
destination address (A3) field 340, a sequence control (SC) field
345, a fourth address (A4) field 350, a quality of service (QoS)
control (QC) field 355, a high throughput (HT)/very high throughput
(VHT) control field 360, a frame body 368, and a frame check
sequence (FCS) field 270. Some or all of the fields 310-365 may
make up the MAC header 250 of FIG. 2. In some implementations, a
protocol version field of the frame control field 310 of the MAC
frame 300 can be 0, or 1 or greater than 1.
The A-Control field 362 may be included in a High Throughput (HT)
Control field 360. Alternatively, the A-Control field may be
included after the HT Control field or immediately after the CCMP
Header (in this latter case, the information can be encrypted).
Counter Mode Cipher Block Chaining Message Authentication Code
Protocol (Counter Mode CBC-MAC Protocol) or CCM mode Protocol
(CCMP) is an encryption protocol designed for WLAN devices that
implements the standards of the IEEE 802.11i. In the examples of
this disclosure, the A-Control field is included in an HT Control
field 360. However, other locations for the A-Control field 362 may
be possible.
FIG. 3 also shows an A-Control field 362 as a series of control
parameters (Control 1, Control 2, and so on). Each control
parameter (such as a first control parameter 370) may be identified
by a control identifier (ID) 374 that serves as a header the
control parameter in a sequence of control parameters. Following
the Control ID 374, the control information 378 may have a
different length depending on the control ID 374 value. Table 1
shows an example of various Control IDs and the information
associated with each.
TABLE-US-00001 TABLE 1 Control Length of Control ID Meaning
Information (bits) 0 Triggered response scheduling (TRS) 26 1
Operation Mode (OM) 12 2 HE link adaptation (HLA) 26 3 Buffer
status report (BSR) 26 4 UL power headroom (UPH) 8 5 Bandwidth
query report (BQR) 10 6 Command and status (CAS) 8 7-14 Reserved 15
ONES 26
In legacy systems, the length of the A-Control field was limited to
30 bits. The container (such as the HT Control field) of the
A-Control field may have a total length of 32 bits, which includes
2 leading indicators, and 30 bits for control parameters. However,
the limited size of the A-Control field constrains the quantity of
control parameters that may be included. For example, the A-Control
field may have been constrained to only one or two control
parameters depending on which control parameters were included.
In accordance with this disclosure, the A-Control field may have a
longer length and may be variable in size to accommodate more
control parameters. In the descriptions below, the length of the
A-Control field may be described in a control header of the
A-Control field. The control header may indicate a length of the
container (such as the HT-Control field) of the A-Control field, or
of the A-Control field itself. Because the length of the A-Control
field and the HT-Control field are related, in this disclosure,
references to the length of the A-Control field may be used
interchangeably with reference to the length of the container (such
as the HT-Control field) carrying the A-Control field. In some
implementations, to indicate the length of the A-Control field, one
of the control parameters may be repurposed to include the length
value as control information. For example, a specific value for the
control ID that is currently reserved, at least in part, may be
used to indicate the length of the A-control field or to provide
delimiters for multiple control parameters. In the implementations
below, we describe the case where the Control ID value is equal to
15. Although the examples in this disclosure use the ONES value
(control ID 15), it is also possible to use one of the reserved
values (control ID 7 to 14) to indicate the length of the A-Control
Field or the presence of another field following the Control ID
field that indicates the length of the A-Control field. In some
implementations, the length may indicate the length of the
remaining portion of the A-Control field, or of a sub-portion of
the A-Control field as described in more detail in some of the
examples below. In some implementations, the length of the
A-Control field may be negotiated beforehand. For example, a
wireless communication device may negotiate a length (or size
limit) for the A-Control field when it creates a wireless
association with another wireless communication device.
FIG. 4 shows an example of using a first portion to indicate the
length of a field that has aggregated control information. For
example, the first portion may indicate a length of the A-Control
field or of the container (such as an HT Control field) that
includes the A-Control field. In some implementations, the length
value may include a header (the VHT/HE bits) and the first portion
(Control 0) as well as the remaining control parameters in the
A-Control field. In some other implementations, the length value
may only include the size of the remaining control parameters in
the A-Control field. For example, the first control parameter 470
(control 0) may be used to indicate a length of the remaining
portion 450 of the A-Control field. As described previously, the
first control parameter may have a ONES value (control ID=15)
followed by a non-zero length 478 value. The non-zero length 478
may indicate the length of the remaining portion 450 based on a
quantity of octets (or groups of octets). Together, the control ID
474 and the non-zero length 478 may be referred to as a ONES-NZL
delimiter in this disclosure. The ONES-NZL delimiter may be used to
signal the length of the A-Control field. Although the examples in
this disclosure refer to the ONES-NZL type of delimiter, other
types of delimiters or control values may be used in other
examples.
FIGS. 5A and 5B show various options of an A-Control field that
includes control parameters for multiple wireless links. In FIG.
5A, each wireless link has separate control parameters. A first
portion of the A-Control field is the ONES-NZL 510 that indicates
the overall length of the A-Control field. The ONES-NZL 510 field
may be followed by control parameters 520 for a first wireless link
1 (such as control parameters A1 and A2). Then delimiters (the
ONES-ZL field 530) may signal that the control parameters for the
first wireless link are complete, and the next control parameters
are for the next wireless link 2. The control parameters 540 for
wireless link 2 (control parameters B1 and B2) may follow the
ONES-ZL field 530).
As shown in FIG. 5B, if one of the links (such as link 2) does not
have control parameters that need to be sent, the ONES-ZL field 530
may be followed by another ONES-ZL field 550 to begin the next link
(link 3) section of control parameters 560 (with control parameters
C1 and C2).
FIG. 6 shows an example of explicit indicators for multi-link
aggregated control parameters. For example, each control parameter
may have an explicit indicator (such as a link identifier, Link ID
676) included in a control parameter 670. The Link ID 676 may be
included between the control ID 674 and the control information
678. In some implementations, the Link ID 676 may be included in
the control IDs that are used as delimiters (such as the ONES-NZL
and ONES-ZL examples in this disclosure).
FIG. 7 shows another example of an A-Control field with control
parameters for multiple links. In FIG. 7, each wireless link has
separate control parameters. A first portion of the A-Control field
is the ONES-NZL 710 that indicates the overall length of the
A-Control field. The ONES-NZL 710 field may be followed by control
parameters 720 for a first wireless link 1 (such as control
parameters A1 and A2). Then another delimiter (the ONES-NZL field
730) may signal that the control parameters for the first wireless
link are complete and the next control parameters are for the next
wireless link 2. The control parameters 740 for wireless link 2
(control parameters B1 and B2) may follow the ONES-NZL field 730).
A ONES-EOF field 780 may be used to signal the end of the A-Control
field that has control parameters for multiple links. For example,
the ONES-EOF may include an all-ONES (control ID=15) followed by an
all-ones length value.
FIG. 8 shows an example of an A-Control field with control
parameters for multiple links without using delimiters. For
example, if each control parameters include an explicit link ID (as
shown in FIG. 6), then the delimiters may be omitted.
Alternatively, the order and occurrence of control parameters may
implicitly indicate that they are for different links. For example,
an A-Control field for a single link would not include more than
one control parameter with the same Control ID. Therefore, if the
same control ID is present in the A-Control field, the second
occurrence of the control ID may implicitly signal the change to
the next link. Using the example in FIG. 8, a first set of control
parameters 820 is related to a first wireless link 1 and a second
set of control parameters 840 may be related to a second wireless
link 2. The control parameter A1 may have the same control ID as
the control parameter B1. When the recipient processes the
A-Control field and detects control parameter B1 having the same
control ID as control parameter A1, the recipient may determine
that the control parameter B1 may be related to the second wireless
link.
As described above with regard to FIGS. 5A, 5B, 6, 7, and 8, there
may be several ways to include control parameters for multiple
links. These techniques, or variations thereof, may be useful to
enable and disable different links. For example, an OM control
parameter may set particular bits (such as the UL MU Disable or the
UL MU Data Disable bits) to a first value (such as 1) to indicate
disablement of that link. In some implementations, a new control ID
(such as one of the reserved values) may be defined to contain
information related to link disablement. For example, the control
parameter may include a target switch time of the state (enabled or
disabled) change. In some implementations, the enablement and
disablement may be used to force a recipient to move from a first
wireless link to a second wireless link. For example, a first
wireless link may be indicated to be disabled at a target switch
time, while a second wireless link may be indicated to be enabled
at the target switch time.
In some implementations, the time value may be relative based on a
start or end time of the frame that carries the control parameters.
For example, the time value may be a time offset relative to the
frame. In some implementations, the timing information may include
a timestamp or other time that is based on synchronized time. A
timing synchronization function (TSF) timer may be maintained in
both the sending device and the receiving device. The timing
information for link enablement or link disablement may be a full
or partial timestamp based on the TSF timer. In some
implementations, the sending device and receiving device may
maintain separate TSF timers for the first link and the second
link. The timing information for enablement or disablement may be
specific to the TSF timer for a particular link.
FIG. 9 depicts a conceptual diagram of an example configuration
message for use in a WLAN. For example, the example message 900 may
be sent from a first communication device to a second communication
device, or vice versa. The example message 900 may include a
preamble 922, a header 924, a payload 910, and a frame check
sequence (FCS) 926. The preamble 922 may include one or more bits
to establish synchronization. The preamble 922 may be used, for
example, when a dedicated discovery channel uses a
listen-before-talk, contention-based access, or carrier sense
access. In some implementations, if the dedicated discovery channel
uses a scheduled timeslot for transmission, the preamble 922 may be
omitted. The header 924 may include source and destination network
addresses (such as the network address of the sending AP and
receiving AP, respectively), the length of data frame, or other
frame control information. In some implementations, the header 924
also may indicate a technology type associated with a
technology-specific payload (if the payload 910 is specific to a
particular technology type or types). The payload 910 may be used
to convey the configuration information. The configuration
information may be organized or formatted in a variety of ways. The
payload 910 may be organized with a message format and may include
information elements 932, 936, and 938. Several examples of
information elements are illustrated in FIG. 9.
Example information elements 960 may be sent as part of a
configuration or setup message. The example information elements
960 may include an A-Control extended capability field 962, a
multi-link control aggregation capability field 964, an A-Control
acknowledgment setting field 966, or any combination thereof.
FIG. 10 shows a block diagram of an example wireless communication
device 1000. In some implementations, the wireless communication
device 1000 can be an example of a device for use in a STA, such as
one of the STAs 104 described above with reference to FIG. 1. In
some implementations, the wireless communication device 1000 can be
an example of a device for use in an AP such as AP 102 described
above with reference to FIG. 1. The wireless communication device
1000 is capable of outputting and receiving wireless communications
(for example, in the form of wireless packets). For example, the
wireless communication device can be configured to output and
receive packets in the form of physical layer convergence protocol
(PLCP) protocol data units (PPDUs) and Media Access Control (MAC)
protocol data units (MPDUs) conforming to an IEEE 802.11 standard,
such as that defined by the IEEE 802.11-2016 specification or
amendments thereof including, but not limited to, 802.11ah,
802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba, and 802.11be.
The wireless communication device 1000 can be or can include a
chip, system on chip (SoC), chipset, package or device that
includes one or more modems 1002, for example, a Wi-Fi (IEEE 802.11
compliant) modem. In some implementations, the one or more modems
1002 (collectively "the modem 1002") additionally include a WWAN
modem (for example, a 3GPP 4G LTE or 5G compliant modem). In some
implementations, the wireless communication device 1000 also
includes one or more radios 1004 (collectively "the radio 1004").
In some implementations, the wireless communication device 1000
further includes one or more processors, processing blocks or
processing elements 1006 (collectively "the processor 1006") and
one or more memory blocks or elements 1008 (collectively "the
memory 1008").
The modem 1002 can include an intelligent hardware block or device
such as, for example, an application-specific integrated circuit
(ASIC) among other possibilities. The modem 1002 may be configured
to implement a PHY layer. For example, the modem 1002 is configured
to modulate packets and to provide the modulated packets to the
radio 1004 for transmission over the wireless medium. The modem
1002 is similarly configured to obtain modulated packets received
by radio 1004 and to demodulate the packets to provide demodulated
packets. In addition to a modulator and a demodulator, the modem
1002 may further include digital signal processing (DSP) circuitry,
automatic gain control (AGC), a coder, a decoder, a multiplexer,
and a demultiplexer. For example, while in a transmission mode,
data obtained from the processor 1006 is provided to a coder, which
encodes the data to provide encoded bits. The encoded bits are then
mapped to points in a modulation constellation (using a selected
MCS) to provide modulated symbols. The modulated symbols may then
be mapped to a number N.sub.SS of spatial streams or a number
N.sub.STS of space-time streams. The modulated symbols in the
respective spatial or space-time streams may then be multiplexed,
transformed via an inverse fast Fourier transform (IFFT) block, and
subsequently provided to the DSP circuitry for Tx windowing and
filtering. The digital signals may then be provided to a
digital-to-analog converter (DAC). The resultant analog signals may
then be provided to a frequency upconverter, and ultimately, the
radio 1004. In implementations involving beamforming, the modulated
symbols in the respective spatial streams are precoded via a
steering matrix prior to their provision to the IFFT block.
While in a reception mode, digital signals received from the radio
1004 are provided to the DSP circuitry, which is configured to
acquire a received signal, for example, by detecting the presence
of the signal and estimating the initial timing and frequency
offsets. The DSP circuitry is further configured to digitally
condition the digital signals, for example, using channel
(narrowband) filtering, analog impairment conditioning (such as
correcting for I/Q imbalance), and applying digital gain to
ultimately obtain a narrowband signal. The output of the DSP
circuitry may then be fed to the AGC, which is configured to use
information extracted from the digital signals, for example, in one
or more received training fields, to determine an appropriate gain.
The output of the DSP circuitry also is coupled with the
demodulator, which is configured to extract modulated symbols from
the signal and, for example, compute the logarithm likelihood
ratios (LLRs) for each bit position of each subcarrier in each
spatial stream. The demodulator is coupled with the decoder, which
may be configured to process the LLRs to provide decoded bits. The
decoded bits from the spatial streams are then fed to the
demultiplexer for demultiplexing. The demultiplexed bits may then
be descrambled and provided to the MAC layer (the processor 1006)
for processing, evaluation, or interpretation.
The radio 1004 includes at least one radio frequency (RF)
transmitter (or "transmitter chain") and at least one RF receiver
(or "receiver chain"), which may be combined into one or more
transceivers. For example, the RF transmitters and receivers may
include various DSP circuitry including at least one power
amplifier (PA) and at least one low-noise amplifier (LNA),
respectively. The RF transmitters and receivers are in turn coupled
to one or more antennas. For example, in some implementations, the
wireless communication device 1000 can include or be coupled with
multiple transmit antennas (each with a corresponding transmit
chain) and multiple receive antennas (each with a corresponding
receive chain). The symbols output from the modem 1002 are provided
to the radio 1004, which then transmits the symbols via the coupled
antennas. Similarly, symbols received via the antennas are obtained
by the radio 1004, which then provides the symbols to the modem
1002.
The processor 1006 can include an intelligent hardware block or
device such as, for example, a processing core, a processing block,
a central processing unit (CPU), a microcontroller, an
application-specific integrated circuit (ASIC), or a programmable
logic device (PLD) such as a field-programmable gate array (FPGA),
among other possibilities. The processor 1006 processes information
received through the radio 1004 and the modem 1002, and processes
information to be output through the modem 1002 and the radio 1004
for transmission through the wireless medium. For example, the
processor 1006 may implement a control plane and MAC layer
configured to perform various operations related to the generation
and transmission of MPDUs, frames, or packets. The MAC layer is
configured to perform or facilitate the coding and decoding of
frames, spatial multiplexing, space-time block coding (STBC),
beamforming, and OFDMA resource allocation, among other operations
or techniques. In some implementations, the processor 1006 may
control the modem 1002 to cause the modem to perform various
operations described above.
The memory 1008 can include random access memory (RAM) and
read-only memory (ROM). The memory 1008 also can store processor-
or computer-executable software (SW) code containing instructions
that, when executed by the processor 1006, cause the processor to
perform various operations described herein for wireless
communication, including the generation, transmission, reception
and interpretation of MPDUs, frames or packets.
FIG. 11A shows a block diagram of an example AP 1102. For example,
the AP 1102 can be an example implementation of the AP 102
described with reference to FIG. 1. The AP 1102 includes a wireless
communication device (WCD) 1110. For example, the wireless
communication device 1110 may be an example implementation of the
wireless communication device 1110 described with reference to FIG.
10. The AP 1102 also includes multiple antennas 1120 coupled with
the wireless communication device 1110 to transmit and receive
wireless communications. In some implementations, the AP 1102
additionally includes an application processor 1130 coupled with
the wireless communication device 1110 and a memory 1140 coupled
with the application processor 1130. The AP 1102 further includes
at least one external network interface 1150 that enables the AP
1102 to communicate with a core network or backhaul network to gain
access to external networks including the Internet. For example,
the external network interface 1150 may include one or both of a
wired (for example, Ethernet) network interface and a wireless
network interface (such as a WWAN interface). One or more of the
aforementioned components can communicate with other ones of the
components directly or indirectly, over at least one bus.
FIG. 11B shows a block diagram of an example STA 1104. For example,
the STA 1104 can be an example implementation of the STA 104
described with reference to FIG. 1. The STA 1104 includes a
wireless communication device 1115. For example, the wireless
communication device 1115 may be an example implementation of the
wireless communication device 1000 described with reference to FIG.
10. The STA 1104 also includes one or more antennas 1125 coupled
with the wireless communication device 1115 to transmit and receive
wireless communications. The STA 1104 additionally includes an
application processor 1135 coupled with the wireless communication
device 1115, and a memory 1145 coupled with the application
processor 1135. In some implementations, the STA 1104 further
includes a user interface (UI) 1155 (such as a touchscreen or
keypad) and a display 1165, which may be integrated with the UI
1155 to form a touchscreen display. In some implementations, the
STA 1104 may further include one or more sensors 1175 such as, for
example, one or more inertial sensors, accelerometers, temperature
sensors, pressure sensors, or altitude sensors. One or more of the
aforementioned components can communicate with other ones of the
components directly or indirectly, over at least one bus.
FIG. 12 depicts a flowchart with example operations for a STA to
send aggregated control information. The example operations may be
performed by a first wireless communication device. The flowchart
1200 begins at block 1210.
At block 1210, the method may include determining a plurality of
control parameters for transmission from a first wireless
communication device to a second wireless communication device.
Each control parameter may include at least a Control identifier
(ID) and a control value.
At block 1220, the method may include generating a first frame for
transmission via a first wireless link. The first frame may include
an aggregated control (A-Control) field formatted with the
plurality of control parameters.
At block 1230, the method may include outputting the first frame
for transmission from the first wireless communication device to
the second wireless communication device.
FIG. 13 shows an example PPDU 1300 usable for communications
between a first device and a second device. For example, the PPDU
1300 may be used for a communication from an AP 102 to a STA 104,
or vice versa. In some implementations, the A-control field may be
in an aggregated A-MPDU subframe. FIG. 13 describes the basic
organization of an A-MPDU transmission and the options for
A-Control field in one or more of the MPDUs. Each PPDU 1300
includes a PHY preamble 1302 and optionally one or more PSDUs (such
as PSDU 1304). Each of the PSDUs may be addressed to a receiver
(individually addressed), a group of receivers (group addressed),
or to all receivers (broadcast addressed). Similarly, each PDSU may
be sent by a transmitter, a group of transmitters, or all
transmitters, or a combination of both. Each PSDU 1304 may carry
one or more MAC protocol data units (MPDUs) 1306. For example, each
PSDU 1304 may carry an aggregated MPDU (A-MPDU) 1308 that includes
an aggregation of zero or more MPDU subframes 1306. Each MPDU
subframe 1306 may include a MAC delimiter 1310 and a MAC header
1312 prior to the accompanying MPDU 1314, which may include the
data portion ("payload" or "frame body") of the MPDU subframe 1306.
The MPDU 1314 may carry one or more MAC service data unit (MSDU)
subframes 1316. For example, the MPDU 1314 may carry an aggregated
MSDU (A-MSDU) 1318 including multiple MSDU subframes 1316. Each
MSDU subframe 1316 contains a corresponding MSDU 1320 preceded by a
subframe header 1322.
Referring to the MPDU subframe 1306, the MAC header 1312 may
include a number of fields containing information that defines or
indicates characteristics or attributes of data encapsulated within
the frame body of the MPDU 1314. The MAC header 1312 also includes
several fields indicating addresses for the data encapsulated
within the frame body of the MPDU 1314. For example, the MAC header
1312 may include a combination of a source address, a transmitter
address, a receiver address, or a destination address. The MAC
header 1312 may include a frame control field containing control
information. The frame control field specifies the frame type, for
example, a data frame, a control frame, or a management frame. The
MAC header 1312 may further including a duration field indicating a
duration extending from the end of the PPDU until the end of an
acknowledgment (ACK) of the last PPDU to be transmitted by the
wireless communication device (for example, a block ACK (BA) in the
case of an A-MPDU). The use of the duration field serves to reserve
the wireless medium for the indicated duration, thus establishing
the NAV. Each MPDU subframe 1306 also may include a frame check
sequence (FCS) field 1324 for error detection. For example, the FCS
field 1324 may include a cyclic redundancy check (CRC).
As described above, the A-Control field can be included in an
A-MPDU subframe. In some implementations, the A-Control field
(which may be referred to as a dynamic A-Control field) may be
included in an HT Control field without the need of being contained
in an MPDU or within an MPDU that does not contain one or more of
the fields of the MAC header described above. By reducing the MAC
header (or payload section), the MPDU may have a reduced overhead
and may provide more efficient use of wireless resources. An HT
Control field or other container that includes a dynamic A-Control
field may be referred to as a Dynamic HT Control field. In some
implementations, the presence of the Dynamic HT Control field can
be signaled by using a Reserved bit in the MPDU delimiter.
Alternatively, the length value in an MPDU length field may be a
value that is less than a certain threshold. For example, the
shortest MPDU frame supported is 14 bytes. Therefore, a length
value that is less than 14 bytes may be used to indicate that the
MPDU frame is a new type of frame that carries a Dynamic HT Control
field.
In some implementations, a new MPDU delimiter may indicate that an
A-MPDU subframe has a Dynamic HT Control field with aggregated
control information. Currently, A-MPDU subframes are using for the
Delimiter Signature field the ASCII value for character "n" to
identify an A-MPDU subframe. A different value (other than "n")
could be used to indicate an A-MPDU subframe that has a dynamic HT
Control field so that receivers can differentiate between an A-MPDU
subframe carrying a legacy MPDU or a modified MPDU as described in
this implementation. In some implementations, since the MPDU
delimiter contains an MPDU length field, the A-Control field may
not need the length value (such as the NZL-ONES Control field) to
indicate the length of the A-Control field. Instead, the length of
the MPDU delimiter may indicate the length of the MPDU, the
A-Control field, or container. Reduced signaling also can be used
when the length of the MPDU can be obtained from information in the
MPDU itself and when the only field that is of variable length is
the A-Control field (or of the container that carries it). As an
example, the QoS Null frame is identified by the Type/Subtype field
of the Frame Control field, and a receiver can determine that the
length of the frame is 30 Bytes (assuming the A4 field, HT Control
field and Frame Body are not present). But if the length value
included in the MPDU delimiter indicates that the MPDU length is 42
Bytes, the recipient can deduce that the remaining 12 bytes are
attributed to the A-Control field length.
Since Dynamic HT Control field is not protected anymore from FCS of
the MPDU (when not carried in a legacy MPDU), the sending STA may
append a CRC (such as 16 bits) to protect the Dynamic HT Control
field. Alternatively, the sending STA may use the CRC of the MPDU
delimiter to protect the container that carries the Dynamic HT
Control field.
FIG. 14 depicts an example message flow diagram associated with
acknowledging an MPDU that includes an A-Control field. The example
message flow 1400 shows the first wireless communication device 110
(as the sending STA) and the second wireless communication device
120 (as the receiving STA). The first wireless communication device
110 and the second wireless communication device 120 may exchange
configuration messages 1412 (such as the example of FIG. 9) to
verify they both support the enhanced A-Control field features of
this disclosure.
At process 1414, the first wireless communication device 110 may
prepare and send an MPDU that includes an A-Control field as
described herein. The MPDU transmission 1422 may include multiple
MPDUs (such as an A-MPDU). At process 1432, the second wireless
communication device 120 may process the A-Control field. The
second wireless communication device 120 may determine to send an
acknowledgment message. The acknowledgment message 1434 may include
an indicator that indicates whether the second wireless
communication device 120 properly processed the A-Control field
included in the MPDU transmission 1422. At process 1442, the first
wireless communication device 110 may process the acknowledgment
message 1434 and determine whether to resend the A-Control field in
a subsequent transmission. In some implementations, the
acknowledgment message may be a multi-STA Block Ack frame and the
indicator that the A-Control field is received correctly may be the
inclusion of a field that contains an Ack Type field set to 1 and a
TID field set to 13 (which is a value that is not currently used in
the technical standards).
FIG. 15 shows a block diagram of an example electronic device. In
some implementations, the electronic device 1500 may be one of an
access point (including any of the APs described herein), a range
extender, or other electronic systems. The electronic device 1500
can include a processor 1502 (possibly including multiple
processors, multiple cores, multiple nodes, or implementing
multi-threading, etc.). The electronic device 1500 also can include
a memory 1506. The memory 1506 may be system memory or any one or
more of the possible realizations of computer-readable media
described herein. The electronic device 1500 also can include a bus
1510 (such as PCI, ISA, PCI-Express, HyperTransport.RTM.,
InfiniBand.RTM., NuBus,.RTM. AHB, AXI, etc.), and a network
interface 1504 that can include at least one of a wireless network
interface (such as a WLAN interface, a Bluetooth.RTM. interface, a
WiMAX.RTM. interface, a ZigBee.RTM. interface, a Wireless USB
interface, etc.) and a wired network interface (such as an Ethernet
interface, a powerline communication interface, etc.). In some
implementations, the electronic device 1500 may support multiple
network interfaces--each of which is configured to couple the
electronic device 1500 to a different communication network.
The electronic device 1500 may include an A-Control generation unit
1560 and an A-Control processing unit 1562. In some
implementations, the A-Control generation unit 1560 and the
A-Control processing unit 1562 may be distributed within the
processor 1502, the memory 1506, and the bus 1510. The A-Control
generation unit 1560 and the A-Control processing unit 1562 may
perform some or all of the operations described herein.
The memory 1506 can include computer instructions executable by the
processor 1502 to implement the functionality of the
implementations described in FIGS. 1-12. Any of these
functionalities may be partially (or entirely) implemented in
hardware or on the processor 1502. For example, the functionality
may be implemented with an application-specific integrated circuit,
in logic implemented in the processor 1502, in a co-processor on a
peripheral device or card, etc. Further, realizations may include
fewer or additional components not illustrated in FIG. 15 (such as
video cards, audio cards, additional network interfaces, peripheral
devices, etc.). The processor 1502, the memory 1506, and the
network interface 1504 may be coupled to the bus 1510. Although
illustrated as being coupled to the bus 1510, the memory 1506 may
be coupled to the processor 1502.
FIGS. 1-15 and the operations described herein are examples meant
to aid in understanding example implementations and should not be
used to limit the potential implementations or limit the scope of
the claims. Some implementations may perform additional operations,
fewer operations, operations in parallel or in a different order,
and some operations differently.
As used herein, a phrase referring to "at least one of" a list of
items refers to any combination of those items, including single
members. As an example, "at least one of: a, b, or c" is intended
to cover: a, b, c, a-b, a-c, b-c, and a-b-c.
The various illustrative logics, logical blocks, modules, circuits,
and algorithm processes described in connection with the
implementations disclosed herein may be implemented as electronic
hardware, computer software, or combinations of both. The
interchangeability of hardware and software has been described
generally, in terms of functionality, and illustrated in the
various illustrative components, blocks, modules, circuits, and
processes described throughout. Whether such functionality is
implemented in hardware or software depends upon the particular
application and design constraints imposed on the overall
system.
The hardware and data processing apparatus used to implement the
various illustrative logics, logical blocks, modules and circuits
described in connection with the aspects disclosed herein may be
implemented or performed with a general-purpose single- or
multi-chip processor, a digital signal processor (DSP), an
application-specific integrated circuit (ASIC), a
field-programmable gate array (FPGA) or other programmable logic
device, discrete gate or transistor logic, discrete hardware
components, or any combination thereof designed to perform the
functions described herein. A general-purpose processor may be a
microprocessor or any conventional processor, controller,
microcontroller, or state machine. A processor also may be
implemented as a combination of computing devices, such as a
combination of a DSP and a microprocessor, a plurality of
microprocessors, one or more microprocessors in conjunction with a
DSP core, or any other such configuration. In some implementations,
particular processes and methods may be performed by circuitry that
is specific to a given function.
In one or more aspects, the functions described may be implemented
in hardware, digital electronic circuitry, computer software,
firmware, including the structures disclosed in this specification
and their structural equivalents thereof, or in any combination
thereof. Implementations of the subject matter described in this
specification also can be implemented as one or more computer
programs, i.e., one or more modules of computer program
instructions encoded on a computer storage media for execution by,
or to control the operation of, data processing apparatus.
If implemented in software, the functions may be stored on or
transmitted over as one or more instructions or code on a
computer-readable medium. The processes of a method or algorithm
disclosed herein may be implemented in a processor-executable
software module that may reside on a computer-readable medium.
Computer-readable media includes both computer storage media and
communication media including any medium that can be enabled to
transfer a computer program from one place to another. A storage
media may be any available media that may be accessed by a
computer. By way of example, and not limitation, such
computer-readable media may include RAM, ROM, EEPROM, CD-ROM or
other optical disk storage, magnetic disk storage or other magnetic
storage devices, or any other medium that may be used to store
desired program code in the form of instructions or data structures
and that may be accessed by a computer. Also, any connection can be
properly termed a computer-readable medium. Disk and disc, as used
herein, includes compact disc (CD), laser disc, optical disc,
digital versatile disc (DVD), floppy disk, and Blu-Ray.TM. disc
where disks usually reproduce data magnetically, while discs
reproduce data optically with lasers. Combinations also can be
included within the scope of computer-readable media. Additionally,
the operations of a method or algorithm may reside as one or any
combination or set of codes and instructions on a machine-readable
medium and computer-readable medium, which may be incorporated into
a computer program product.
Various modifications to the implementations described in this
disclosure may be readily apparent to those skilled in the art, and
the generic principles defined herein may be applied to other
implementations without departing from the spirit or scope of this
disclosure. Thus, the claims are not intended to be limited to the
implementations shown herein but are to be accorded the widest
scope consistent with this disclosure, the principles and the novel
features disclosed herein.
Additionally, a person having ordinary skill in the art will
readily appreciate, the terms "upper" and "lower" are sometimes
used for ease of describing the figures, and indicate relative
positions corresponding to the orientation of the figure on a
properly oriented page and may not reflect the proper orientation
of any device as implemented.
Certain features that are described in this specification in the
context of separate implementations also can be implemented in
combination in a single implementation. Conversely, various
features that are described in the context of a single
implementation also can be implemented in multiple implementations
separately or in any suitable subcombination. Moreover, although
features may be described as acting in certain combinations and
even initially claimed as such, one or more features from a claimed
combination can in some cases be excised from the combination, and
the claimed combination may be directed to a subcombination or
variation of a sub combination.
Similarly, while operations are depicted in the drawings in a
particular order, this should not be understood as requiring that
such operations be performed in the particular order shown or in
sequential order, or that all illustrated operations be performed,
to achieve desirable results. Further, the drawings may
schematically depict one more example process in the form of a flow
diagram. However, other operations that are not depicted can be
incorporated in the example processes that are schematically
illustrated. For example, one or more additional operations can be
performed before, after, simultaneously, or between any of the
illustrated operations. In certain circumstances, multitasking and
parallel processing may be advantageous. Moreover, the separation
of various system components in the implementations described
should not be understood as requiring such separation in all
implementations, and it should be understood that the described
program components and systems can generally be integrated together
in a single software product or packaged into multiple software
products. Additionally, other implementations are within the scope
of the following claims. In some cases, the actions recited in the
claims can be performed in a different order and still achieve
desirable results.
* * * * *